Interesting study on the diet of the Tarahumara Indians, widely regarded as the worlds greatest ultra-endurance runners.*

Quote:

The food and nutrient intakes of the Tarahumara Indians of Mexico.

MT Cerqueira, MM Fry and WE Connor.

A nutritional survey of 372 semiacculturated Tarahumara Indians in the Sierra Madre Occidental Mountains of Mexico was carried out to determine the composition of their diet and its nutritional adequacy. Dietary histories from 174 adults and 198 children were obtained by interviews and field observations during 1973 and 1974. The histories for the children were calculated in part from the menus of six boarding church schools. Nutrient calculations of daily intake were based upon food composition tables and some actual analyses of Tarahumara foods. The protein intake was ample, at 87 g, and generously met the FAO/WHO recommendations for daily intake of essential amino acids. Fat contributed only 12% of total calories, its composition being 2% saturated and 5% polyunsaturated with a P/S ratio of 2. The mean dietary cholesterol intake was very low, less than 100 mg/day, and the plant sterol intake was high, over 400 mg/day. Carbohydrate comprised 75 to 80% of total calories, mostly from starch. Only 6% of total calories were derived from simple sugars. The crude fiber intake was high, 18 to 21 g/day. Salt consumption was moderately low, 5 to 8 g/day. The daily intakes of calcium, iron, vitamin A, ascorbic acid, thiamin niacin, riboflavin, and vitamin B6 exceeded or approximated the FAO/WHO recommendations. Thus, the simple diet of the Tarahumara Indians, composed primarily of beans and corn, provided a high intake of complex carbohydrate and was low in fat and cholesterol. Their diet was found to be generally of high nutritional quality and would, by all criteria, be considered antiatherogenic.

Is that right, 5-8 *grams* per day of sodium??? AFAIK, that's not low....

Their sodium chloride (salt) intake is 5-8g/d which would make their sodium intake 2-3.2g/d (see table 2 in the pdf). You're right though, that isn't low however it doesn't appear to cause them any problems.

Quote:

The moderately low intake of sodium chloride in the diet of the Tarahumaras (5 to 8 g/day) correlated well with their previously reported low blood pressure levels (12). This level of salt intake is in contrast to the usual
American intake of 6 to 18 g/day (29). The low blood pressures of the Tarahumaras are in contrast to the high incidence of hypertension in the United States (48). The habitual low sodium chloride intakes of many primitive agricultural populations have been repeatedly noted to be associated with a relative absence of hypertension (49-5 1). Other factors in the Tarahumaras that may contribute to the low mean blood pressures are the lack of obesity and the high degree of physical fitness. Anderson et al. (52) noted the rarity of hypertension throughout Mexico in groups of peoples eating the basic bean-tortilla diet. Perhaps there is also an antihypertensive factor in this aboriginal Indian diet.

This was posted by Mike Romano here a week or so back. I've only just managed to find time to read it properly and it's interesting stuff.

Quote:

The plasma lipids, lipoproteins, and diet of the Tarahumara Indians of Mexico.

ABSTRACT

The Tarahumaras are unacculturated Indians of the Sierra Madre Occidental Mountains renowned for their running in competitive races. Over a 4-year period at different locations, 523 healthy Tarahumaras (ages 5 to 70 years) were surveyed for plasma lipids and lipoproteins. We determined also the nutrient intakes of a subsample (174 adults). Mean plasma cholesterol was 125 ± 26 (SD) mg/dl and triglyceride 120 ± 52. Men and nonpregnant women had similar values. Pregnant women were higher. Children were similar, cholesterol of 116 ± 22 and triglyceride of 115 ± 50. For all ages, lipoprotein cholesterol was 87 mg/dl low density lipoproteins, 21 very low density lipoproteins, and 25 high density lipoproteins. Lipoprotein triglyceride was 40 mg/dl low density lipoproteins, 84 very low density lipoproteins, and 24 high and the low density lipoproteins and high density lipoproteins cholesterol. Plasma triglyceride, very low density lipoproteins triglyceride, and cholesterol of Tarahumaras were somewhat higher but not abnormal. The diet of the Tarahumaras (versus the diet of Iowans) was low in cholesterol (71 mg/day), in fat (12% of calories) and in saturated fat (2% of calories). Protein was adequate (13% of calories). The carbohydrate (75% of calories) and fiber (19 mg/day) were high. Corn and beans were the chief caloric sources. The total plasma cholesterol correlated positively with dietary cholesterol intake (r = 0.874), the first time in man such a correlation has been found. Particularly notable was the virtual absence of the hypertension, obesity, and the usual age rise of the serum cholesterol in adults. Thus, the customary diet of the Tarahumaras is adequate in all nutrients, is hypolipidemic, and is presumably antiatherogenic. Am. J. Clin. Nuir. 31: 1131-1 142, 1978.

I think a couple things are interesting. 1, in most of the other studies I posted, the tarahumara appeared to have markers of malnutrition, such as decreased stature, several vitamin and mineral deficiencies, etc., dating all the way back to 1980. Incidently, many suffer from heart problems, supposedly from all of that running (in another study I posted).

Also, genetics may play a large role in the success that they have had on their diet. Like the study Darryl posted here, this is the first time that dietary cholesterol correlated with serum cholesterol. Genetic drift is a definite possibility here given the extremely limited outbreeding and population size. Lastly, if this is not the case, who is to say that serum cholesterol being that low is beneficial? I remember reading some studies that correlated excessively low cholesterol to high mortality/morbidity, I'll look for them.

Finally, another important thing is that their diet is HYPOcaloric. Diseases of overnutrition (such as obesity, heart disease, etc.) would clearly not have a place in their lives...however, undernutrition may.

The frustrating thing about this study is it raises more questions than it answers and with the Tarahumara increasingly adopting our crappy modern eating habits we'll probably never get the chance to see any further studies on how their traditional diet as it might have been 200+ years ago effects their health.

Anyway the first question that comes to mind is this; if there is a correlation between dietary cholesterol and serum cholesterol as this study suggests then what from an evolutionary perspective is a normal/healthy cholesterol level?

Obviously I don't have any answers but these are my first thoughts -

- We know that we evolved from ripe fruit specialists like chimpanzees into the starch adapted primates we are today and that we have specific genes which enable us to thrive on a diet high in starchy carbohydrates.

- For most of our history, at least up until we started throwing pointy sticks at things ~20-30,000 years ago anyway, our diet was mostly plant based and what meat we did eat came from hunted small game, fresh water fish or carrion so our diet was a lot lower in saturated fat and cholesterol than it is today.

- Our protein requirments are quite small and can be met quite easily from almost any mixed diet even a totally plant based one as long as caloric needs are met.

- There is no physiological requirement for dietary fat apart from EFA's.

- The Tarahumara lifestyle is a throwback to the mesolithic era as they're cave dwelling semi-nomadic subsistance farmers who practice persistence hunting.

- The Masai who also have an essentially mesolithic lifestyle develop atherosclerosis at a rate comparable with modern Americans on their traditional diet which is high in saturated fat.

- Vegetarians and vegans, hippy idiots though they are, along with people who favour fish over meat generally have lower rates of cardiovascular disease than meat eaters.

So with all the caveats about their current problems with malnutrition is it possible that the Tarahumaras incredibly low-fat plant based diet and their low cholesterol levels are closer to the ideal for our species than we might previously have thought?

*Please note that I'm not trying to pick a fight over this one (for a change), I am genuinely interested in hearing everybodies thoughts.

Dunno, I have a hard time believing that vegetarianism is the way to go....anecdotally and evolutionarily. The very first day of my anthro 102 class we went over the decline of health that went along with the agricultural revolution in nearly every race, i.e. native americans, egyptians, etc. It's pretty standard stuff.....

also, evidence that we only started hunting large game 20k years ago? From what I have learned, it began during the acheulian tradition, about 1.2 million years ago....there is evidence that elephants were hunted around that time. That is to say nothing of saturated fat intake, but I am pretty sure intense hunting DID exist.

Dates re. the development of the modern hunter-gatherer lifestyle along with relevant info re. mesolithic and neolithic eras can be found in The Human Past: World Prehistory & the Development of Human Societies by Chris Scarre.

Info on the lack of any physiological requirement for dietary fat other than the EFA's along with info on protein requirments can be found in the Manual of Dietetic Practice (4th edition) by Briony Thomas and Jacki Bishop.

Quote:

Originally Posted by Mike Romano

Dunno, I have a hard time believing that vegetarianism is the way to go....anecdotally and evolutionarily. The very first day of my anthro 102 class we went over the decline of health that went along with the agricultural revolution in nearly every race, i.e. native americans, egyptians, etc. It's pretty standard stuff.....

The Tarahumara aren't vegetarians they just eat very little meat. As for the health problems associated with the introduction of agriculture they can mostly be attributed to rapid population growth and the spread of infectious diseases along with all the other problems you get when there's too many people living too close together with too little food. When there's enough food to go around and there's proper health care all those problems disappear.

Quote:

Originally Posted by Mike Romano

also, evidence that we only started hunting large game 20k years ago? From what I have learned, it began during the acheulian tradition, about 1.2 million years ago....there is evidence that elephants were hunted around that time. That is to say nothing of saturated fat intake, but I am pretty sure intense hunting DID exist.

According to The Human Past by Chris Scarre the shift from an opportunistic gatherer-scavenger lifestyle to what we now consider to be the hunter-gatherer lifestyle occurred ~27,000 years ago and the evidence of the first arrow dates back to ~10,500 years ago. (note: those dates could be bc rather than years ago, should have made notes last night but I was tired). S. Boyd Eaton suggests that there was a gradual shift starting ~40,000 years ago to a modern hunter-gatherer lifestyle and if memory serves he puts the earliest use of spears in hunting at ~20,000 years ago although I suspect the use of spears and the bow and arrow goes back further but we haven't found the evidence for it yet.

Anyway what's important is those dates relate to our recent history and as we're all happy to accept that 10,000 years of agriculture hasn't been long enough to fully adapt to a grain based diet (note: I'm not certain about that theory anymore) perhaps it's time we started questioning how relevant the modern hunter-gatherer diet is to our health and how from an evolutionary perspective it relates to our nutritional requirements. Maybe we need to look further back in time to find our ideal diet because hunting and the regular consumption of animal protein didn't really become a big part our diet until quite recently and for most of our history as a species our diet was almost entirely plant based much like other primates.

How does all that relate to the Tarahumara then? Again this is pure speculation on my part and with the caveat that corn and beans are obviously not paleolithic foods and there could be a degree of genetic drift involved in their good health the question is this; what if the Tarahumara's plant based diet with a limited intake of animal protein and fats is closer to our ideal evolutionary primate diet than that of modern-hunter gatherers and is therefore better for our health?

Obviously I don't have any answers but it's all food for thought. (pun intended )

Dunno, I have a hard time believing that vegetarianism is the way to go....anecdotally and evolutionarily. The very first day of my anthro 102 class we went over the decline of health that went along with the agricultural revolution in nearly every race, i.e. native americans, egyptians, etc. It's pretty standard stuff.....

also, evidence that we only started hunting large game 20k years ago? From what I have learned, it began during the acheulian tradition, about 1.2 million years ago....there is evidence that elephants were hunted around that time. That is to say nothing of saturated fat intake, but I am pretty sure intense hunting DID exist.

There's lots of various evidence for a lot of positions on each topic.

Darryl's one of the high carbo enthusiasts here if you didn't know while most others here advocate a generally lower carb intake.

Take everything with a grain of salt, and figure out what works best for you. But if you want to debate history, go for it.

haha don't worry steven, already got my diet figured out...used to try and "cut" for bodybuilding purposes with the diet Darryl proposes, and I got skinny-fat. With Paleo, I have no such issues. Just like debating the theory, because it is so interesting that there are so many viewpoints.